Evaluation of mercury chelating properties of polyphenols extracted from allium ascolanicum (shallots) and camellia sinensis (green tea)

Date of Completion


Document Type


Degree Name

Bachelor of Science in Pharmacy


total phenolic content, tannic acid, polyphenols, bioremediation, mercury-chelating properties


Introduction: Inadequate treatment of metal-containing effluents discharged by mining industries poses immense threats to human and wildlife health. Among the heavy metals commonly introduced through chemical wastes, mercury has the most potential to cause acute toxicity. Human activities, such as alkali and metal processing, coal incineration, waste disposable, and gold and mercury mining, collectively contribute to the proliferation of mercury concentrations, but atmospheric deposition stands as the predominant source in most regions. Polyphenols like those isolated from Allium asconicum (shallots) and Camellia sinensis (green tea) are known to have metal- chelating properties. This study aims to determine a natural and efficacious alternative for the remediation of environmentally prevalent mercury contaminants.

Methods: Methanolic extracts of A. ascolanicum and C. sinensis were prepared by Soxhlet extraction. Kupchan fractionation was also performed to separate the bioactive compounds in both extracts. Phytochemical analysis was conducted to identify the presence of phenolic compounds in the extracts. Then, the total phenolic content was determined by using the Folin-Ciocalteu assay using a UV-visible spectrophotometer.

Results: Phytochemical analysis and the Folin-Ciocalteu assay showed the presence of varying concentrations of polyphenols in the methanolic extracts A. ascolanicum and C. sinensis. Notably, the A. ascolanicum extract exhibited a significantly higher phenolic content compared to the C. sinensis extract. This suggests that A. ascolanicum possesses more metal-chelating

polyphenols, which could hold potential for effective mercury remediation. Further investigations are warranted to ascertain the efficacy of these polyphenols in actual mercury binding and removal processes. Conclusion: The metal-chelating properties of polyphenols from A. ascolanicum and C. sinensis demonstrates their potential as viable candidates for eco-friendly reduction of mercury contaminants, marking a critical step toward environmental remediation. Further research should aim to elucidate the practical applicability of these polyphenols in real-world mercury mitigation scenarios.

First Advisor

Sigfredo B. Mata

This document is currently not available here.